This research is concerned with identifying the principles underlying the perceptual processing of patterns and relations. Experimental techniques are used to control momentary attention states of the subjects so that the invariant characteristics of these processing mechanisms may be revealed. Emphasis is given to the measurement of learning which takes place after the accuracy criterion has been achieved in the tasks. This aspect of learning appears to be closely related to the acquisition of automaticity in the performance of perceptual identification, associative processing, and perhaps the comprehension of relations.